Effects of Deposition Temperature on Strain in Polycrystalline SiC Films Deposited by Radio-Frequency Glow Discharge

Polycrystalline SiC films were deposited by rf glow-discharge decomposition of silane-methane mixtures under heavy hydrogen dilution. As a result of X-ray diffraction measurement, the lattice parameter is found to be closely related to the crystallinity. Variation in the lattice parameter reflects the presence of strain in the films. It is shown that the crystallinity improves with increasing deposition temperature, although the improvement is saturated above 700°C. This saturation is interpreted in terms of the strain due to C-C bonds.